Intermittent shut down 87S4
12-08-2009, 11:35 AM
#1
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Intermittent shut down 87S4
This is NOT my car but I have an owner in town with an 87S4 with the following issue. He emailed me this...
any one seen or had a similar problem?
Ive already told him to check/replace the EZK ,LH and igntion X relays as a general trouble shoot.
Since the tach seems to go wacky i was thinking a bad crank postion sensor?
I plan on swapping the EZK/LH units with mine so i can hook it up to my sharktuner and get a better look for any faults.
Im guessing a bad CPS?
thanks
About 10 min in to a drive the engine shuts down, the dash lights up, rpm needle bounces high (not motor) car comes to a stop. After trying to re-fire for approx. 5 min. it starts and runs fine until 5 to 10 min later it repeats the problem. I do not mind replacing parts until i find the problem but where should i start (ecu, ignition, ?) thanks,
Ive already told him to check/replace the EZK ,LH and igntion X relays as a general trouble shoot.
Since the tach seems to go wacky i was thinking a bad crank postion sensor?
I plan on swapping the EZK/LH units with mine so i can hook it up to my sharktuner and get a better look for any faults.
Im guessing a bad CPS?
thanks
12-08-2009, 12:43 PM
#3
Rennlist Member
I'd check/replace the fuel pump relay also...............assuming when it runs it runs well theres good compression so fuel or ignition issue.
12-08-2009, 01:01 PM
#4
Team Owner
As Malcolm said, relays first
Last edited by Mrmerlin; 12-08-2009 at 02:43 PM.
12-08-2009, 01:52 PM
#5
Nordschleife Master
When the CPS dies the tach needle will not jump. It will fall like a rock and not move. It will also be very difficult to start.
I would first put in new relays and if that doesnt fix it I would be looking at swapping brains with known good brains.
Also check thrust bearing play.
I would first put in new relays and if that doesnt fix it I would be looking at swapping brains with known good brains.
Also check thrust bearing play.
12-08-2009, 04:00 PM
#6
Electron Wrangler
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Sounds to me like it could also be an intermittent power interuption... I'd check/clean all the connections on the front jump post and the top of the CE panel - are they tight & clean...
If its very consistently 5-10 mins seems it must be related to something warming up... does it exhibit hot start issues too? seems he alludes to that with the 5 min wait....
If its very consistently 5-10 mins seems it must be related to something warming up... does it exhibit hot start issues too? seems he alludes to that with the 5 min wait....
Last edited by Alan; 12-08-2009 at 04:53 PM.
12-09-2009, 04:40 AM
#7
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A friend of mine had a similar problem with his '89 GT.
Thread can be seen here:
https://rennlist.com/forums/928-foru...9-euro-gt.html
In the end it turned out to be one of the stock alarm system relays, part nr. 928.637.16.000
Thread can be seen here:
https://rennlist.com/forums/928-foru...9-euro-gt.html
In the end it turned out to be one of the stock alarm system relays, part nr. 928.637.16.000
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12-09-2009, 06:23 AM
#8
Rennlist Member
Suggest you remove the 35way connectors at LH.
Check that no water has leaked into the LH 35 way connector. The first pin to be attached by water is usually pin 1 which is the rpm feed from EZK to LH (also feeds the tach)
Check that no water has leaked into the LH 35 way connector. The first pin to be attached by water is usually pin 1 which is the rpm feed from EZK to LH (also feeds the tach)
